Artificial limb



March 13, 1951 R. R. HYDORN ARTIFICIAL LIMB 2 Sheets-Sheet 1 Filed Feb.25, 1949 Alfil INVENTOR. H/dolm.

A T'TORNE YS R. R. HYDORN ARTIFICIAL LIMB March 13, 1951 Filed Feb. 25,1949 IN V EN TOR.

A TTOR/VE YS'.

m. fw M Patented Mar. 13, 1951 UNITED sTATEsPATENT orifice l Thisinvention relates to artificial limbs and particularly to such limbsconstructed of lightweight materials and employing inflatable means toassist in supporting the weight of a wearer.

In general the invention contemplates an artificial limb comprising.limb sections in the form of hollow shells appropriately hinged togetherat the joints. An inatable bag is formed tooccupy the .interior of theentire limb structure, extending across the joints, to assist insupporting the weight of the wearer and performing the' additionalfunction of returning the pivotedsections to a normal predeterminedposition after flexure.

It is an object of this invention to provide, an artiicial limb ofextremely light-weight construction yet having sufticient strength andrigidity for its intended purpose.

It is another object of this invention to provide an articiallimb'including pivoted joints wherein an inflatable member assists insupporting the weight of a wearer and in addition acts to return partsto a predetermined normal relative relationship.

It is a still further object of this invention to provide an articiallimb having relatively hinged portions capable of being quite freelypivoted in one direction, during walking or the like, and includingmeans to retard the return of those parts to normal position.

Further objects and advantageswill become apparentl as the descriptionproceeds in connection with the accompanying drawings wherein: A Fig. lis a side elevational view of an artificial limb embodying theprinciples of the present invention. Y

Fig. 2 is a vertical sectional view through the embodiment illustratedin Fig. 1. Y

Fig. 3 is a fragmentary Vertical sectional view taken substantiallyalong the line 3--3 of Fig. 2.

Fig. 4 is a fragmentary sectional View taken substantialy along the line4-4 of Fig. 2.

Fig. 5 is a sectional View through the foot section substantially valongthe line 5-5 of Fig. 2.

Fig. 6 is a fragmentary,.vertical, sectional view, similar to Fig. 2 butillustrating a modified form of knee joint, and

Fig. '7 is a view similarto Fig. 6., illustrating the parts in differentrelative positions.

Referring now to Fig. 1, numeral I indicates an upper leg section havinga leather boot 2 xed thereto in a manner to be described. A lower legsection 3 is pivoted to the upper section I, as at 4, by means of ananti-friction ball bearing joint 5 provided in opposed ears extendingfrom the sections I and 3. The ears referred to are further providedwith inter-engageable abutments, at 5a, to limit. pivotal movement in4one direction. A fcotsection 6 has pivoted thereto a toe section 'I onak transverse axis 8 and the foot section is, in turn, universallymounted relative to the lower leg section 3 in a manner to be described.

*.terial.

ential groove 9.

Referring now to Fig. 2 the upper leg section I, the lower leg section 3and the-foot section 5 are of hollow, shell-like construction and arepreferably made of-relativelylight-weight materials such as aluminum ormagnesium but may, if desired, be made of steel or any other suitablema- The upper leg section I is provided with a circumferential groove 9adjacent its lower end and its upper edge I0 is preferably bevelled orfeathered to avoid the presentation of an abrupt vshoulder at thatpoint. The-leather boot 2, previously referred to, has a ring or band ofleather I I sewed or otherwise affixed theretovat its innervmost lowerend and positioned in the circumfer- Upon lacing the boot to the upperleg section, as indicated in Fig. 1, the ring or band II acts as a keyor locking means to retain the boot in fixed position on the upper legsection I.` Y I The foot section 6 is provided with a generally circularopening I2 at its uppermost portion and the opening I2 is surrounded bya generally horizontal abutment or shoulder'I3/ which may be providedwith an annularl channel-like seat to receive the lower end ofk ahelical compression spring I4. The lowermost portion of the lower legsection 3 is provided with a generally spherical outer surface I5 of adiameter somewhat less than that of the opening AI2 inthe foot section.The leg section 3 is further provided with a downwardly facing shoulderor channel I6 forming a seat or abutment for the upper end of theVspring I4. (The lower terminus of the leg section 3 extends downwardlyinto the opening I2 and the clearances therebetween are sufficient topermit the upper leg section to swing in any vertical I plane relativeto the foot section. The spring I4y vwill prevent the leg section 3 fromdropping 'through the opening I2 and wedging itself therein and is ofsufficient strength to-support a -substantial portion of the weight ofthe wearer. Adjacent the shoulder I6 and on opposite sides of the legsection 3, the limb is provided with abutments I1 (Figs. 1 and 3)extending outwardly beyond the outer edges of the spring I4. Theabutments I'I are positioned directly above upwardly andoutwardlyextending ear portions I8 on the foot section 6. The ears orrockers I8 are provided with upper surfaces curved in a fore and aftdirection. It will be apparent from Fig. 1, that if the weight appliedto the limb is excessive or if shock loads are applied, the engagementof the abutments I1 with the ears I8 will prevent further telescoping ofthe leg section 3 into the foot section and provide a stop means at thatpoint. In addition to acting as a limiting stop, inter-engagementbetween the portions I'I and I8 willpermit the leg section 3 to rock orroll on the curved surfaces of the ears I8 in a fore and aft direction,thus permitting the user to walk in a normal manner, even with thesection 3 in its lowermost position. In addition, the ears I8 at alltimeslimit the lateral swinging of leg section 3 to an amount less thanits permissible fore-and-aft pivotal movement.

A hollow, inflatable bag member 2B is molded or otherwise formed to havea normal shape substantially complementary `to the space inside theassembled limb, including at least 'aportion of the foot section. `Thisinflatable bag may be made entirely of rubber or maybe formed fromfabric or other reinforcing material, treated in a suitable manner torenderit impervioustc air. The upper end of the bag 2D is provided witha reinforced, relatively thick and generally flat portion 2I havingshoulders Z'Z'resting upon suitable abutments provided in the upperlegsection I. A pad'or cushion of sponge rubber `or other suitableYmaterial v23 is positioned within the upper leg section l and restsupon the reinforced upper 'end 2l of the bag 20. In use the bag 25 isinflated and the boot 2 may be laced to the wearer with the stump ofthewearers natural limb resting upon the cushion or pad`23. By thisarrangement it will be apparent that the vinflatable bag-20 provides a`resilient supportior joints the bag 20 is -formed with inwardly turnedportions 24 and 25. These inwardly turned portions deiine restrictednecks or -passageways between sections of the limb. The inturned portions at the rear 'of the knee jointA are thickened considerably, as at'2.6, and provided with suitable reinforcing means l(not shown) toyrender them substantially rigid and inflexible `adjacent the outersurfaces of the bagf. The inturned portions at 25 are likewise providedwith suitable reinforcing means rendering :them substantially rigid and`are vso formed and shaped that when fully inflated'they snugly engagethe inner lower.- mostportion of the leg section in gripping engagementwith a bead or ring 221 formed at the lower terminus of the section 3and engage "the bottom thereof whereby the section B-is also supportedby the portion of bag ZII in the foot section. The reinforcing meansreferred to may be in the form of metal inserts or successive layers ofcloth imbedded in the material of the bag or such stiffenirig may beprovided'by any other suitable means.

As clearly shown in Fig. 2 the thickened portions of the bag 2n at thejoints are of such configuration that when the limb is in its normalposition adjacent thickened portions are in direct contact with eachother. The innermost portions 23 and 29 of the inturned constrictions ofthe bag 20 have relatively thin wall sections and vare positionedsubstantially symmetrically of the openings in the wall 32.

pivotal axes at the respective joints whereby ilexure of the bag may beperformed with relative ease.

As also shown in Fig. 2 the inflatable bag 20 does not Vcompletely iillthe hollow foot section but terminates short of the toe section in agenerally vertical end wall or partition 30. The remaining space withinthe foot section is occupied by an inflatable bag 3I s0 shapedas to besnugly'received'within the remaining space. The small bag 3i has an endwall 32 abutting against the end wall 39 of the bag 20. The walls 30 and32 are each provided with a pair of openings and the openings in thewall are aligned with the In one pair of aligned openings a one-way orcheck valve 34 is positioned and in the other openings a member 35,having a restricted passageway 32S therethrough, is positioned. Thecheck valve 34 comprises a valve body having an outwardly extendingflange 31 and a spring-pressed valve element S5 urged toward an opening3B in the said valve body. The end of the valve body opposite `theflange31 is preferably threaded as at to receive 'a clamping ring 4I toposition the valve in the composite partition wall in fixed andair-tight relation thereto. It will be apparent that the one-way valvedescribed provides for rapid and `easy passage of air through said valvein one direction and blocking of the return of said air in the Yopposite'direction through said valve. The one-way valve structure described ismerely illustrative and may be replaced by any .suitable arrangement topermit air to be readily passed in one direction only from the interiorof the (small bag 3l to the interior of the large inflatable bag 2B.

In the other pair .of aligned lopenings previously referred to thememberor plug A35is held in fixed position by means of a threadedclamping ring 42 clamping the periphery of the openings against anopposed flange 43 in an obvious manner and in the manner described inconnection with the valve 34. As stated,the member S5 is provided with arestricted opening 3S therein, which opening provides a small passagewaybetween the interiors of the bags and3l. The effective size of theopening 35 may be varied by adjustment of a control member l44 threadedthrough the element .35.and having a head 45 provided with a screwdriverslot 46. The control element d extends outwardly .between thewalls 30and 32 andthe head 45 thereof plies inwardly of an .opening 47 (seeFig. 1) `provided in a side wall of the outer shell of foot section B.The inner endof the element 4.4 maybeextendedinto or withdrawn from theopening 36. The control member 44 described. is merely .illustrative andany other suitable means may be employed to control the effective sizeof the passageway .33. Preferably suchcontrol means will be accessibleto and manipulable 'from the outside of the foot section.

The forward portion of .the foot section 6 is open/as at 48, and abracket 49 is fixed to the interior of the foot shell. The bracket 49provides a bearing support upon which the toe section 'I may bepivotally'mounted on the transverse axis 8. vThe toe section 'I isfurtherprovided with an inwardly extending tongue 50 which extendsinwardly of the foot vsection beyond the axis 8 and into contact withthe outer surface of the small bag 3 I.

A valve 5I, of any suitable type of construction, is provided in theinatablebag v2Il and is positioned inwardly of opening 52 inthe legsection 3 whereby the valve is readily accessible for the inflation ofthe bag 2o or for the regulation of air pressure within said bag. Thevalve 5I will preferably be formed to extend inwardly of the bag 20 toavoid outwardly projecting parts.

In use, the wearer may swing the artificial limb forwardly to anadvanced position and upon transferring his weight thereto the kneejoint and the toe section will pivot under his or her weight in a mannersimulating the action of a natural limb as the body moves forwardly. Asthe wearers body moves forwardly of the artificial limb, which thenextends toward the rear, the knee and toe joints -will bend further butsuch bending will be opposed by the pressures within the inflatablebags. It will be apparent from Fig. 2 that upon swinging the leg sectionI rearwardly about the joint 4 the reinforced portions 25 at the rearofthe knee will cause compression of thev bag 20 in a manner to resistbending at the knee joint. In like manner bending of the toe section 1upwardly will cause the tongue 50 to be pressed inwardly of the bag 3iand will be resisted by the pressure within the inflatable bag. Pressurewithin the bag 3l, however, will cause some of the air therein to betransferred to the-bag 20 through valve 34 and upon release of theweight from the limb in question, in walking, and swinging of the limbforwardly, the toe section will be allowed to return to normal positionunder the influence of the pressure of ail` returning to the bag 3|through opening 36. Such return to normal position, will, however, bedelayed since expansion of the bag 3l is limited by the restrictedopening 36 so that the toe section 'l does not return to extendedposition before the limb has been swung forwardly, thus obviating thedanger of the wearer stumbling or stubbing the toe section during theforward swinging movement of the limb. In like manner the limb isstraightened to normal position at the knee joint, While being swungforwardly, due to the tendency of the bag 29 to resume its normal shapeadjacent the reinforcements 26.

The upper leg section I is further provided with a depending,transversely curved, plate-like portion 60 slidably received behind anupwardly extending similar portion 6! on the lower leg section 3. DuringfleXure of the knee joint the portions 60 and 6l may slide relative toeach other to provide a continuously closed forward knee surface. Aresilient and flexible stretchable pad 62 is cemented or otherwiseattached, as at 63 andV 64, to the upper and lower leg sectionsrespectively. The attachment of the pad 62 to the upper and lower legsections will preferably be limited to relatively small areas at the topand bottom of the pad whereby as the knee iis bent the pad may stretchor contract in simulation of a natural knee.

Figs. 6 and '7 illustrate a modified form of knee joint for an articallimb of this general type. In this modified construction an inflatablebag 2a extends across the knee joint, as in the previous embodiment, butthe bag is not provided with the restricted neck portions described inconnection with the earlier embodiment. The upper leg section la lsprovided with a downwardly extending spring element 19, attached at itsupper end to the upper leg section and extending downwardly into thelower leg section 3a and in contact with the outer surface of the bag20a therein. The member 10 may be in the form of a ribbon of springsteel or the like.y Upon flexure of the joint to the position shown inFig.

'7, the spring member 10 will act to compress the bag 20a and distort itto the shape shown in Fig. 7, thereby conditioning the bag to urge thesections la and 3a back to the normal position shown in Fig. 6.Preferably the bag 20a will be provided, in the normal position of thesections, with an inwardly turned portion 'H in its forward wall at theknee joint, to permit the bag to assume the position shown in Fig. '7without a tendency to stretch its forward wall.

Although a limited number of embodiments have been illustrated herein,it is to be understood. that the specific forms of the invention shownand described do not limit the scope of the invention, which is to belimited only by the scope of the appended claims.

I claim:

1. In an artical limb, a pair of members, means providing for relativepivotal movement between said members, one of said members comprising ahollow shell, an inflatable bag in said hollow shell, said bagcomprising at least two cells separated by an impervious partition, theother of said members having a portion engaging one of said cells tocompress the same upon relative pivotal movement between said members, acheck valve in said partition to permit inflating uid to flow freelyfrom said one cell to the other cell, and a restricted passage betweensaid cells to permit inflating iiuid to ow, at a low rate from saidother cell to said one cell.

2. In an artificial limb, a pair of members, joint means providing forrelative pivotal movement between said members, each of said memberscomprising a hollow shell, an inflatable bag in said hollow shells andextending across said joint, and means actuated by relative pivotalmovement of said members to compress a portion of said bag, said meansbeing xedly carried by one member and extending across said joint toengage said bag in the other of said members whereby tc urge saidmembers in relative pivotal movement opposite to that effectingcompression of said bag by return of said Abag to uncompressedcondition.

3. In an articial limb, a pair of members, means providing for relativepivotal movement between said members at a limb joint, each of saidmembers comprising a hollow shell, and an inflatable bag within saidhollow shells and extending across said joint.

4. In an articial limb, a pair of members, means providing for relativepivotal movement between said members at a limb joint, each of saidmembers comprising a hollow shell, and an inflatable bag within saidhollow shells and extending across said joint, said bag having arestricted flexible neck portion at said joint.

5. In an artificial limb, a pair of members, means providing forrelative pivotal movement between said members at a limb joint, each ofsaid members comprising a hollow shell, and an inflatable bag withinsaid hollow shells and extending across said joint, said bag having arestricted flexible neck portion at said joint, portions of said bagadjacent to and on opposite sides of said neck portion being relativelyinflexible and normally in contact with each other.

6. In an artificial limb, a foot section and a leg section, saidsections comprising hollow shells, an opening in said foot section atthe ankle thereof, said leg section having a terminal portion at thebottom thereof within the said opening, an inflatable bag within saidshells and extending across said ankle joint, said leg sec- 7; tionresting upon-and being at .least partially supported by a vportionlofsaid inatable bag in said foot section.

7. An artificial limb as defined in claim 6 and further including ahelical spring loosely surrounding the lower portion of said legsection, said spring bearing upon an upper surface of said foot sectionand engaging said leg section to at least partially support said legsection.

8. An artificialllimb as defined in claim 6 wherein said leg section isprovided with an abutment normally spaced above said foot section butengageable therewith to limit downward movement of said leg sectionrelative to said foot section.

9. An artificial limb as defined in claim 6 wherein said leg section isprovided with an abutment normally spaced above. said foot section butengageable therewith Vto limit downward movement of said leg sectionrelative to said foot section, said abutment being positioned at theside of said leg section, and said foot section having a curved surfaceengageable with said abutment whereby said leg section may rock in a,fore and aft direction relative to said foot section while in itslowermost position.

10. In an `artificial limb, an upper section, a lower section, saidsections being pivotally joined on a transverse axis to provide a joint,said sections further having relatively 'slidable overlapping portionson one side of said axis, and a pad of resilient material overlying saidoverlapping portion.

11. An articial limb as defined in claim l0 wherein said pad is fixed toat least one of said sections adjacent said overlapping portions.

l2. In an artificial limb, a pair of members, joint means providing forrelative pivotal movement between said members, said members eachcomprising a hollow shell, an inflatable bag in said hollow shell andextending across said joint, one of said members having a portionengaging said inatable bag to compress the same upon relative pivotalmovement between said members.

REX R.. HYDORN.

REFERENCES CITED g The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 598,452 Tullis Feb. 1, 1898708,685 White Sept. 9, 1902 2,416,817 Carter Mar. 4, 1947

